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Japanese Weaves: Maintaining AR Density With Wire Diameter Adjustments
Article © MAIL User: Chainmailbasket_com

Introduction:


Some rules have been established about the relationships between the ARs of the two ring types in Japanese weaves. But what happens if you want the two ring sizes to be of two different wire diameters? This is common, since it makes the weave less porous: the holes are made smaller since smaller wire takes up less space. Also, it helps with AR balancing. The smaller rings will have a larger AR due to the smaller wire diameter. Despite being ideal for the smaller rings in a Japanese weave, rings of ARs below 3.0 are generally more difficult to cut, more susceptible to warping, and harder to work with. This article demonstrates the math required to achieve two wire-diameter Japanese maille. Japanese 12 in 2 will be used for this demonstration, but the same principle can be applied to other standard weaves of the Japanese family, provided the appropriate ARs are substituted.

The minimum ARs for Japanese 12 in 2 using the same wire diameter for the smaller and larger rings are AR of 2.6, and AR of 5.2. The sample constructed for this article will be based off this, since it is this weave's AR starting point. This picture shows a sample nearing the minimum combo with each ring type being of the same wire diameter:

Image: j12-2.jpg

(See Japanese Weaves: Minimum AR Considerations for more information.)




The Math:


For the following example, I'll be using rings of .080" wire diameter for the large, horizontal rings and those of .062" for the smaller (vertical) connector rings. This will cause the large rings to have a smaller AR. As mentioned above, the smaller rings will end up being a larger AR, while the weave density should remain the same.

First, we'll calculate the inner diameter required for the large rings. To do this, we use the desired large ring AR of 5.2 with the wire diameter of the smaller rings.

5.2 * .062" = .32"

Next, we'll calculate the required inner diameter for the small rings. To do this, we use the desired small ring AR of 2.6 with the wire diameter of the larger rings.

2.6 * .080" = .21"

So, we need .080" rings with an inner diameter of .32" for the large rings. I've chosen .080" 19/64" bright aluminum for these, which have a measured ID of .323" (AR of 4.0).

The second ring size needed is .062" with an inner diameter of .21" for the small rings. I've chosen .062" 25/128" bright aluminum for these, which have a measured ID of .215" (AR of 3.5).

In both cases, I've been a little bit liberal in sizes chosen. I didn't want to dip below the calculated sizes, so I used the closest ones I had in bright aluminum. The resulting weave might end up slightly looser as a result. But what do you guys think, will this work?

Please note: these are rings from my personal collection. The ID (and resulting AR) was taken from measurements achieved with calipers. Your results will vary. This is based on variances in the manufacturing process, metal used, etc.

Also, if you use the metric system for ring sizing, the same math will apply. Just substitute inches for millimeters and be sure to use mm for both ring ID, and wire diameter. AR is universal.


The Trial:


12 vertical rings connect to 2 horizontal ones. So far, so good.
Image: trial01.jpg

Two more horizontal rings are added.
Image: trial02.jpg

The next steps are applied to the J12-2 construction method and everything is in check. The remaining six loose vertical rings connected to the starter piece are nice and close together.
Image: trial03.jpg

The piece is expanded into a full circle. We have confirmed that this ring size combo works.
Image: trial04.jpg

The piece is expanded hexagonally by one more full row around.
Image: trial05.jpg

This picture shows the weave held up by pliers. It's fairly tight and not very bendy, which was expected.
Image: trial06.jpg

Conclusion:


This method worked to create a J12-2 weave using rings of two different wire diameters. The resulting piece of chainmail is not quite as tight as it could be, but it is very close. The large rings are almost bang on, but the smaller ones cause for a discernible gap between horizontal sets. Possible reasons are that wire diameter, inner diameter, and aspect ratio information is approximate. As mentioned, I used ring sizes slightly larger than calculated values, due to limitations in available ring sizes.
Original URL: http://www.mailleartisans.org/articles/articledisplay.php?key=761